The continual demand for enhanced integrated circuit performance has resulted in, among other things, a dramatic reduction of semiconductor device geometries, and continual efforts to optimize the performance of every substructure within any semiconductor device. As smaller dimension DRAM come into full production, haze and other progressive reticle defects have become more prevalent and costly in the semiconductor industry. These problems arise due to several factors, which include the use of shorter exposure wavelengths that produce highly energized photons as well as other environmental sources in a manufacturing facility. Some of the contaminants have been identified as cyanuric acid and ammonium sulfate, but the true mechanisms for formation of haze may have multiple possible causes and still need further research.
Fortunately, even though haze defects are dynamic and can develop quickly, the formation can be cleaned. The current challenge in a production facility is how to detect and control the haze defects without interfering with mass production.
While the possible sources and origins of the haze defect are still being investigated, it is desirable to limit the loss accompanying these defects. One method of detection is to inspect reticles and wafers frequently for development of haze defects; however, it is ineffective to solely rely on inspection without any logical system in place to calculate an accurate sampling method of reticle and wafer inspection. In addition to having a well-operated system, it is also desirable to embrace practicality by making the system cost-effective and ensure that it does not hinder production capacity. Further, studies have shown that formation of progressive defects including haze is significantly greater as the wavelength in use decreases.
As a result, there is a need for a system and method for haze control in semiconductor processes.